Specifications: Model: Microsound V22.12 Product Type: MP3 Infrared Doorbell Audio Format: MP3 (Bit Rate: 8 ~ 320Kbps), excellent sound quality, two levels volume for option: small or maximum. Built-in Speaker: 8ohm 1W Speaker Sensor: Infrared Induction, support automatic induction Power Supply Mode: DC3V ~ 5V Stabilized Voltage Supply Working Current: ≤100uA (Sleep Standby Mode); ≤130mA (DC 4.7V) (Playing Mode) Infrared Induction Distance: ≤ 4meters (45d Angle) Sample Rate: 14KHz Memory Size:Built-in 4Mbit SPI FLASH memory Installation:Ceiling mounted or wall mounted Power supply: External USB power supply DC 5V or 3 AAA dry batteries (Not Included) Working Current: Sleep Status ≤ 100uA; Playing status ≤ 60mA Humidity: 10 ~ 85%RH Colour:White Material:ABS Size:90*60*26.6mm Package Contents: 3 * Audio Doorbell Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the